In this chapter different types of power cables used in electric power industry are considered from utility, construction operation, and evaluation of performance point of view. High-tension cables, low-tension cables, H-type cables, SL cables, HSL cables, and EHV cables are mentioned. With cross-sectional sketches the constructional features are shown, which highlight the different types of insulation utilized. Electrostatic stress and the gradual reduction in the potential gradient from conductor surface to outer sheath is analyzed. Intersheath grading and capacitance grading to achieve economy (reduction in cable size) are explained with analytical treatment. Determination of capacitance of cables is described. Thermal resistance and power factor of cables are discussed. Cable breakdown is mentioned. Thermal phenomenon in cables and sheath losses are discussed. Thermal resistance is defined and cable rating is explained.